 There is very low quality evidence indicating that doxycyline use may be associated with an increased risk of indigestion, photosensitivity, vomiting, and yeast infections, when compared with mefloquine and atovaquone-proguanil.Causal prophylactics target not only the blood stages of malaria, but the initial liver stage as well.This means that the user can stop taking the drug seven days after leaving the area of risk.